Need help with replacing my water heater

I am looking to buy a new water heater to replace our existing one (an A.O. Smith model about 10 years old, with a first hour rating of 74 gallons). We have a 4-bedroom 3 bathroom house. While our current family of 5 are not exactly water hogs (e.g. we don't typically take very long showers), I also want to anticipate that if we sell the house, the size would be appropriate for a typical 5-person family with teenagers.

In doing some research and talking to local plumbing companies, it seems like I should target a heater with about 100 gallons or more for the first hour, so probably a 60+ gallon tank. The models I have been quoted are:

The labor seems on the upper end of the range if it's just a plain swop out the old for the new (but see my comment below). In the nation's capital I had a Bradford White 40 gallon installed for 800. I am guessing that equates to about 500 labor.

It also depends on what else you need though. I did not need an expansion tank with my install and you may need one. But I did need a new gas shut-off valve. Luckily my plumber did not ask extra for the valve, but most will add on for any extra bits, which can soon add up.

A bit more pipe here, an expansion tank there and a new ball valve over there can soon add an extra few hundred.

By the time a professional plumber adds in his overhead, there is a pretty hefty labor charge for water heater installation. This will vary by the area of the country where you live, so it's hard to say if $800 is an excessive charge or not. Frankly, this is one of the jobs that inspires many of us DIYers. While a straight change over for a water heater is really not difficult, I do not recommend you attempt it if you do not have some basic plumbing knowledge or if this will be more complex than a straight swap of tanks. Bradford White would be an excellent choice, but these are supposed to be sold only to professional plumbers, not the general public. There has be a very long discussion on this forum recently about this. A good choice for a DIY install is the GE/Rheem. Smith, State, Whirlpool in particular are not highly recommended due to quality issues.